Such a continuity tester especially serves for checking and allocating the individual cores of installed multi-core cables, for example telecommunication cables extending between a main line installed in a roadway, and building connections. For such a purpose, the signal transmitter is connected to the individual cores at the end of the cable, and the identification signals fed into the conductors by the signal transmitter are decoded and displayed by the signal receiver at the other end for allocation of the cores.
A conductor allocation tester LZT 16 of the type specified above is known from the trade publication ELV, No. 4, 1989. One of the two connections of the signal receiver is continuously supplied with a reference potential (e.g. mass) and has to be connected to a line or core, of which the opposite end is known. Said opposite end has to be connected to a corresponding reference connection of the signal transmitter. The other conductors can then be successively tested with the other connection of the signal receiver. The drawback of said known arrangement is, on the one hand, that one conductor among the conductors or cores to be tested has to be known with its two ends because it is required as a reference line. Only one single conductor can then be tested at a time in the following steps of the test. No identification of cross connections between the other conductors to be tested is possible.
Such a test arrangement is known from DE 39 24 763 A1, which has the same drawbacks, and which, furthermore, operates with analogous voltages via a resistance network. This causes problems in connection with very long conductors to be tested, whereby the number of conductors to be tested is limited by the fact that the differences in voltage in the tested lines become smaller and smaller.
The problem of the present invention is to enhance a continuity tester of the type specified above in such a way that no reference core is needed for the test, and that at least two conductors or cores can be tested in each step of the test.